The invention relates to a heating apparatus and, more particularly, to a high efficiency heating apparatus for warming a preselected area.
LP/propane or natural gas fueled heaters such as patio heaters are available in both free-standing and built-in configurations, and are primarily sold for commercial applications. For example, patio heaters have become especially popular in recent years in areas such as the Southwest where no smoking laws are being applied to taverns and bars forcing patrons outdoors to smoke which can be especially inconvenient during cold nights. Patio heaters can be utilized to provide warmth in preselected outdoor areas making it much more comfortable for smokers, and for those who like to be outdoors.
Free-standing patio heaters that can be readily moved from location to location to heat preselected areas typically have a base that is sized to contain a fuel tank therein and an elongate hollow support standard projecting upward therefrom to a burner assembly housing in which air is heated by combustion of the fuel gases from the tank in the base. The burner assembly housing has a cylindrical wall provided with apertures to provide for the escape of the hot products of combustion in the housing. The flow of hot gases through the wall apertures heats the wall so that the wall emits radiant infra-red heat. A relatively large dome-shaped reflector hood is attached on top of the housing and opens downwardly for reflecting heat emanating from the housing generally downwardly about the standard of the patio heater. In the built-in configuration which typically will not be moved after the unit is installed, the heater is connected to a source of gas such as provided by a gas utility company thus eliminating the need for the base so that the standard extends all the way from the ground up to the burner assembly housing. In each of the free-standing and built-in configurations, the burner assembly housing and reflector dome have substantially the same construction.
One shortcoming of presently available patio heaters is in their heating efficiency. The apertured cylindrical wall has portions exposed below the bottom of the dome reflector hood such that heat emitted therefrom may not encounter the dome, and instead of being directed downwardly thereby for heating of the area around the standard, the heat travels in a generally unimpeded path radially away from the heater so as to provide little or no heating effect to the area below which is desired to be warmed. Further, once the patio heater is turned on, the area heated is the entire 360xc2x0 circumference around the unit; however, this entire area may not need to be heated such as where the heater is adjacent a corner of the patio so that it is difficult for people to stand around the entire 360xc2x0 area under the hood.
A further deficiency lies in the large size of the metal reflector domes, typically on the order of 34xc2xd inches in diameter. The large dome is expensive and difficult to store and ship in a compact manner. Current packaging of the apparatus is likewise rendered more difficult where the apparatus has a large size dome reflector which restricts the ability to properly display and shelve the apparatus for retail sale.
Accordingly, there is a need for a heating apparatus such as a patio heater which better maximizes its heating efficiency. A further need exists for a heating apparatus that can be stored and shipped in a compact and cost-efficient manner. In addition, a patio heater that can be compactly packaged would be desirable for retail sale.
In accordance with the present invention, a heating apparatus is provided which is improved in terms of its heating efficiencies over prior commercially available patio heaters. The present heating apparatus is for igniting fuel from a fuel tank having valve controls that control supply of fuel from the tank. The heating apparatus includes a heat emitter including a burner assembly for igniting fuel from the fuel source to provide heat emanating from the emitter, an elongate support member mounting the heat emitter at an upper end thereof and including a gas line extending therethrough for feeding fuel from the tank to the burner assembly for ignition and a shroud for fitting over the fuel tank and including an access opening at a predetermined location on the shroud with the opening being sized to allow an operator access to the fuel tank control for controlling supply of fuel to the burner assembly.
In one form of the present invention, a heating apparatus aligned along a longitudinal axis is provided and includes a burner assembly for igniting fuel from a fuel source, and a housing for the burner assembly. An emitter surface of the housing includes apertures for directing heat generated by the ignited fuel out away from the housing. The emitter surface is inclined relative to the longitudinal axis so as to direct heat in a generally downward direction about the longitudinal axis for maximum efficiency in warming of a preselected area by the heat emitted from the housing. Angling of the emitter surface so that it is inclined relative to the vertical longitudinal axis of the heating apparatus substantially obviates the need for the large reflector dome as used with prior commercially available patio heaters as heat is directed out away from the burner assembly housing in a generally downward direction for heating of the preselected outdoor area. Further, because the emitter surface directs heat in the downward direction due to its inclination to the vertical, radiant heat directed straight out radially as with cylindrical apertured emitter surfaces is avoided thereby minimizing the amount of heat lost and increasing the efficiency of the apparatus in terms of the amount of fuel necessary to keep a given area defined by a tight radius about the apparatus sufficiently warm.
In a preferred form, a cover member is provided above the housing with the cover member extending radially beyond the housing to protect it from exposure to precipitation. The cover member is spaced above the emitter surface along the longitudinal axis to reflect stray radiant heat that rises above the housing back in the downward direction around the longitudinal axis. Preferably, the heating apparatus includes an elongate support member projecting up to the burner assembly housing, and the cover member has a predetermined diameter transverse to the longitudinal axis that is less than approximately 2xc2xd feet in length. Prior dome reflectors are much larger than the cover member of the present heating apparatus with the large size being necessary to reflect the heat from the cylindrical wall of the burner assembly housing. The provision of the present inclined emitter surface substantially eliminates the need for the large dome reflector of the prior patio heaters such that a much smaller cover member can be used, as described above.
In one form, the heating apparatus includes a base sized to contain a fuel tank therein with the burner assembly housing being substantially smaller than the base, and an elongate support member extending between the base and the housing along the longitudinal axis. Detachable connections are provided between the support member, the base, and the housing to allow for transportation storage in a compact manner.
Preferably, the emitter surface is flat and is inclined at a predetermined angle from the longitudinal axis to direct heat downward and radially outward from the longitudinal axis. The predetermined angle can be approximately 70xc2x0 for maximizing the coverage of heated air throughout the preselected area.
In a preferred form, the emitter surface has a frustoconical shape for directing heat downward and radially outward from the longitudinal axis, and the housing further includes an upper cylindrical wall portion projecting upward from the top of the frustoconical emitter surface.
In another form of the invention, an upper housing assembly for a heating apparatus is provided with the upper housing assembly containing a burner head for ignition of fuel supplied thereto from a fuel source. The housing assembly includes a cylindrical wall portion having a central longitudinal axis extending therethrough, and apertures in the cylindrical wall portion for emitting hot gases created by the ignited fuel. At least one louver extends transverse to a longitudinal axis and is adjustably attached to the housing wall portion to allow the position of the louver to be changed relative to the axis for directing heat emanating from the wall and apertures thereof in a generally downward direction. The louver allows the burner assembly housing of the prior commercially available patio heaters to be employed while eliminating the need for the large dome reflector hoods attached thereover, and substantially minimizes the loss of radiant heat directed out radially from the housing without being reflected by the dome. In addition, the adjustable louver allows for the area being heated by the heating apparatus to be altered in accordance with the specific needs of the user(s).
Preferably, the heating apparatus includes a base for containing a fuel tank with the base having a predetermined radius, and the distance from the central axis to the louver distal end is shorter than the base radius so that the louver is sized to fit inside the base for transport.
In a preferred form, the at least one louver includes multiple louvers that are adjustable relative to each other to change the spacing between adjacent louvers and for minimizing the risk of accidental contact with the hot wall of the housing assembly.
In one form, the louver has an annular body portion inclined downward relative to the central axis, and a bent portion spaced from the housing wall portion that is inclined downward relative to the annular body portion. Preferably, there are provided multiple louvers that are adjustable relative to each other to change the spacing between adjacent louvers, and the louver annular bodies and bent portions have predetermined radial lengths with the radial length of the annular body being approximately twice the spacing between adjacent louvers and approximately four times that of the radial length of the bent portion.
In another form of the invention, a heating apparatus for controllably heating different areas about the apparatus is provided including a burner assembly for igniting fuel from a fuel source and a housing for the burner assembly having an apertured wall extending about the burner assembly to emit heat from the housing. A heat reflector hood is provided which is larger than the housing in a radial direction and is disposed above the housing wall for directing rising heated air from the housing downwardly to heat a preselected area below the hood. A heated area adjuster is provided under the hood and is adjustable to deflect heat for changing the preselected area being heated by the heat from the housing. The heated area adjuster allows heat from the housing to be concentrated in areas about the heating apparatus where it is needed, whereas areas that are not used, and thus do not need to be heated, are not heated.
Preferably, the heated area adjuster includes a baffling mechanism adjacent the housing wall which is shiftable between first and second positions so that with the baffling mechanism in the first position substantially the entire extent of the reflector hood is utilized to direct heated air from the housing to heat the preselected area, and with the baffles shifted to the second position less than substantially the entire extent of the reflector hood is utilized to direct heated air from the housing to heat a different preselected area. The baffling mechanism can include pivotable baffles that are pivoted closed in the first position, and are pivoted open in the second position.
In one form, the heated areas adjuster may include a heat diverter adjacent the housing wall with the heat diverter being adjustable to block heat from a portion of the reflector. The heat diverter is adjustable to a plurality of different positions for varying the size of the reflector portion blocked from heat to change the preselected area that is heated.